[PATCH] fix verify_export_symbols()

[PATCH] fix verify_export_symbols()

[Jan Beulich]

When the newer export flavors were added, it was apparently forgotten
to add respective code here.
In order to not double the (source) size of the function, add some
abstraction to reduce code duplication.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
---

 kernel/module.c |   37 +++++++++++++++++++------------------
 1 file changed, 19 insertions(+), 18 deletions(-)

--- linux-2.6.24-rc7/kernel/module.c	2008-01-10 16:50:54.000000000 +0100
+++ 2.6.24-rc7-verify-export-symbols/kernel/module.c	2008-01-08 16:42:35.000000000 +0100
@@ -1344,31 +1344,32 @@ EXPORT_SYMBOL_GPL(__symbol_get);
  */
 static int verify_export_symbols(struct module *mod)
 {
-	const char *name = NULL;
-	unsigned long i, ret = 0;
+	const char *name;
+	unsigned int i;
 	struct module *owner;
 	const unsigned long *crc;
 
-	for (i = 0; i < mod->num_syms; i++)
-		if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
-			name = mod->syms[i].name;
-			ret = -ENOEXEC;
-			goto dup;
-		}
+#define VERIFY(syms) \
+	for (i = 0; i < mod->num_##syms; i++) { \
+		name = mod->syms[i].name; \
+		if (__find_symbol(name, &owner, &crc, 1)) \
+			goto dup; \
+	}
 
-	for (i = 0; i < mod->num_gpl_syms; i++)
-		if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
-			name = mod->gpl_syms[i].name;
-			ret = -ENOEXEC;
-			goto dup;
-		}
+	VERIFY(syms);
+	VERIFY(gpl_syms);
+	VERIFY(gpl_future_syms);
+	VERIFY(unused_syms);
+	VERIFY(unused_gpl_syms);
+#undef VERIFY
+
+	return 0;
 
 dup:
-	if (ret)
-		printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
-			mod->name, name, module_name(owner));
+	printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
+	       mod->name, name, module_name(owner));
 
-	return ret;
+	return -ENOEXEC;
 }
 
 /* Change all symbols so that st_value encodes the pointer directly. */

[PATCH] fix verify_export_symbols()

[Jan Beulich]

When the newer export flavors were added, it was apparently forgotten
to add respective code here.
In order to not double the (source) size of the function, add some
abstraction to reduce code duplication.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

---
 kernel/module.c |   39 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

--- linux-2.6.25-rc5/kernel/module.c	2008-03-10 13:24:35.000000000 +0100
+++ 2.6.25-rc5-verify-export-symbols/kernel/module.c	2008-03-04 11:23:05.000000000 +0100
@@ -1383,33 +1383,32 @@ EXPORT_SYMBOL_GPL(__symbol_get);
  */
 static int verify_export_symbols(struct module *mod)
 {
-	const char *name = NULL;
-	unsigned long i, ret = 0;
+	const char *name;
+	unsigned int i;
 	struct module *owner;
 	const unsigned long *crc;
 
-	for (i = 0; i < mod->num_syms; i++)
-		if (!IS_ERR_VALUE(__find_symbol(mod->syms[i].name,
-							&owner, &crc, 1))) {
-			name = mod->syms[i].name;
-			ret = -ENOEXEC;
-			goto dup;
-		}
+#define VERIFY(syms) \
+	for (i = 0; i < mod->num_##syms; i++) { \
+		name = mod->syms[i].name; \
+		if (!IS_ERR_VALUE(__find_symbol(name, &owner, &crc, 1))) \
+			goto dup; \
+	}
 
-	for (i = 0; i < mod->num_gpl_syms; i++)
-		if (!IS_ERR_VALUE(__find_symbol(mod->gpl_syms[i].name,
-							&owner, &crc, 1))) {
-			name = mod->gpl_syms[i].name;
-			ret = -ENOEXEC;
-			goto dup;
-		}
+	VERIFY(syms);
+	VERIFY(gpl_syms);
+	VERIFY(gpl_future_syms);
+	VERIFY(unused_syms);
+	VERIFY(unused_gpl_syms);
+#undef VERIFY
+
+	return 0;
 
 dup:
-	if (ret)
-		printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
-			mod->name, name, module_name(owner));
+	printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
+		mod->name, name, module_name(owner));
 
-	return ret;
+	return -ENOEXEC;
 }
 
 /* Change all symbols so that st_value encodes the pointer directly. */

Re: [PATCH] fix verify_export_symbols()

[Rusty Russell]

On Thursday 13 March 2008 20:04:17 you wrote:
> When the newer export flavors were added, it was apparently forgotten
> to add respective code here.
> In order to not double the (source) size of the function, add some
> abstraction to reduce code duplication.

Hi Jan,

   Actually, the others did exist, they just weren't checked.

I've taken this patch and your two other module patches.  Please cc me on 
module patches in future.

Thanks!
Rusty.

Re: [PATCH] fix verify_export_symbols()

[Rusty Russell]

On Tuesday 18 March 2008 09:36:04 Rusty Russell wrote:
> On Thursday 13 March 2008 20:04:17 you wrote:
> > When the newer export flavors were added, it was apparently forgotten
> > to add respective code here.
> > In order to not double the (source) size of the function, add some
> > abstraction to reduce code duplication.
>
> Hi Jan,
>
>    Actually, the others did exist, they just weren't checked.

No, my bad, you're right (GPL-only existed, but they were covered already).  
The problem with this is that we'll get a bogus unused warning in the case of 
doing a __find_symbol on an unused symbol.

It's time for a general cleanup of the __find_symbol logic.  I'll post when 
it's done.

Thanks!
Rusty.